Typewriting machine



July 5, 1932. w. F. HELMOND TYPEWRI'I-ING MACHINE Filed Aug. 21, 1929 2 Sheets-Sheet 1 5 Inventor:

9%zzzw am! by M July 5, 1932. w. F. HELMOND TYPEWRITING MACHINE Filed Aug. 21, 1929 2 Sheets-Sheet 2 Patented July 5, 1932 UNETED STATES PATENT OFFICE VJTLLIAM F. HELMOND, OF WEST HARTFORD, CONNECTICUT, ASSIGNOR TO UNDERWOOD ELLIOTT FISHER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE TYPEWRITING MACHINE Application filed August 21, 1929. Serial No 387,300.

This invention relates to a ribbon-winding and automatic-reversing mechanism for Underwood and other typewriting machines, and discloses improvements upon the structure of patent granted to me, No. 931,303.

The ribbon is carried upon two spools, one at each side of the machine, set on vertical drive shafts. At their lower ends the shafts have pinions to mesh with pinions upon a transverse main drive shaft, for causing the ribbon to wind to and fro.

The main drive shaft is operated in the Underwood machine by means of a pawlmechanism which is actuated by the keys through the medium of a universal bar. One

of the features of the invention is an improvement whereby the ribbon-winding pawl is driven by the down strokes of the keys, thus securing positive operation of the winding 10 and reversing mechanism, instead of by means of springs which have to be pre-tensioned at the down strokes of the keys, and which are somtimes uncertain in operation, especially when the keys are driven at high speed, and

which offer excessive resistance to the fingertouch upon the keys.

The teeth of said ribbon-winding wheel are of fine pitch and shallow, and trouble has been experienced from their becoming filled up by the shellac or other material used in finishing the wheel; and it is one of the objects of the invention to overcome this difficulty. To this end, the wheel is not coated with japan or other material, but is left in unfinished condition when placed in the typewriter. A side mask is secured to the wheel, fitting over its spokes and rotating therewith, and having an attractive finish; the mask being a mere shell set upon the ratchetwheel and of about the same diameter, and

lending the appearance of a high finish to the wheel.

Associated with each spool is an automatic ribbon-reversing device, which includes a K shaft-shifting wheel. This is fixed upon the main drive shaft. It may be noted that one of the features of the present improvements is to provide separation between the positions of the ribbon-spools, so as to clear the spools from the ends of the paper-carriage, when it bon is caused to swing an arm, whereby an is desired to remove the spools or to manipulate the ribbon. The ribbon-spools have been given positions at the extreme sides of the machine, together with said ribbon-reversing wheels; and one of the latter has been placed facewise close against the masked ribbonwinding wheel, the latter fixed upon the end of the main drive shaft. These ribbon'reversing wheels are in the form of disks, which are given a lustrous finish, which is observable through the openings in the masked ratchet-wheel, thus lending to the entire ribbon-wheel structure at each side of the machine an ornamental appearance, and adding substantially to the attractiveness and salability of the entire machine.

The ribbon-reversing mechanism begins to function when the ribbon is nearly unwound from either spool. An obstruction on the ribinterponent is swung into the path of a rotating shaft-shifting wheel, and engages one of a set of notches which are formed thereon; the interponent being so pivoted that, when swung by said wheel, it turns in such a direction as to have a crowding or jamming reaction upon the wheel itself, thrusting the wheel and shaft in a direction longitudinal of the shaft. This disconnects. the shaft from one spool and re-connect it with the other spool. This interponent includes a cam, which is operated by a cam-arm upon a reverser-shaft standing adjacent the spool-shaft, and carrying the aforesaid ribbon-operated arm. The cam-arm, usually fastened upon the reverser-shaft in Underwood machines, has been found to be apt to get loose and drop off, and otherwise give trouble. In place of attachi-ng an arm to the reverser-shaft, said shaft is prolonged and the prolonged portion is bent radially at its lower end, and the bend is reduced in diameter at its outer end. A portion of the reduced part is bent downwardly to form a finger which engages said interponent-cam to operate it.

Upon the upper end of said reverser-shaft is fastened a hub by means of, a setscrew; this hub being riveted or swedged to said rib bon-operated arm. Then the hub and arm are keyed by a pin which is driven down into the swedged portion, thereby locking the arm firmly to the hub. This pin is also used for anchorage for a spring which returns the ribbon-operated arm at the conclusion of an automatic ribbon-reversing operation.

Said spring is connected at one end to a movable segment of the ribbon-spool housing, said segment being provided with a handle for swinging to one side, to give access to the ribbon; so that one spring is made to serve for both purposes.

Other features and advantages will here, iii-after appear.

In the accompanying drawings,

Figure 1 is a plan of the ribbon-spool and other mechanism of an Underwood typewriting machine, indicating diagrammatically that the ribbon-spools have been placed .sufiiciently far apart at the sides of the machine, to enable the paper-carriage to clear either one.

Figure 2 is a part-sectional side elevation of the machine.

Figure 3 is a sectional perspective rear view of the ribbon-mechanism.

Figure 4 is a perspectivesectional detail, showing a ribbon-operated arm and its shaft.

Figure 5 is a perspective view of the ribbon-winding ratchet-wheel separated from its mask and from the ribbon-reversing wheel, and the winding shaft.

Figure 6 is a perspective view showing an assembly of the parts seen separated at Figure 5.

Figure 7 is a detail of a driving arm and ribbon-winding pawl.

Type-bars 1O .strike rearwardly against platen 11 mounted in carriage 12, and rotated by line-space lever 13, all of which is shown at Figure 2 as clear of the left-hand ribbonspool and its housing.

The type-bars are operated by keys 14, which depress levers 15 to swing forwardly bell-cranks 16, which act upon the type-bars. The type-bar heels operate a segmental universalbar 17 whose rear end is pivoted on links 18, and vibrates rearwardly a dog-rock- 'er 19, which controls the feeding movements of escapement-wheel 20, pinion 21, and car- K riage-rack 22.

The universal bar is also utilized for winding the ink-ribbon 23 upon spools 24, 25.

'Said arms 18 rock r-earwardly at the typestrokes, and raise an arm 26 and its link 27. The link is connected to rock up an arm 28 that is fixed upon a horizontal rock-shaft 29, which carries an arm 30, to the lower end of .which is pivoted at 31 a forwardly-extend- 3 ing spring 36 is provided for the pawl 32 to keep it in engagement with the ratchet-wheel 33. At each printing stroke of any type-bar,

the shaft 29 is rocked, and the pawl pulls the ratchet-wheel 33 to wind the ribbon. Winding is therefore effected during the powerstroke of the typekey l4, and insures feeding of the ribbon when the machine is operated at high speed or under other harsh conditions. Universal-bar spring 37 returns the ribbon-winding pawl-train to normal posi tion when the type-key is released. The returning of the winding pawl does not require heavy tensioning of spring 37, as it does not have to perform the labor of winding the ribbon. The tension that is felt at the keys may be diminished correspondingly.

Spring 36 is coiled around a hub 38, Figure 7, riveted upon arm 30. The pawl has a hubportion in the form of ears 39 that fork said hub; and the pivot-pin 31 is driven through the hub 38.

The winding shaft 34 is provided with a pair of pinions 40, 41 for co-operation with pinions 42, 43; the latter pinions being fixed upon the bottom ends of vertical shafts 44, 45 carrying the detachable spools 24, 25. Reversal of the travel of the ribbon may be effected by shifting the shaft endwise.

In order to make it feasible for the ratchet-wheel 33 to be employed in unlacquered or unfinished condition, so as to avoid choking its fine teeth with finishing material, the Wheel is provided with a mask in the form of a fiat or shallow shell or disk 46, having a coated, highly finished, ornamental outer face 47. The mask packs closely against the face of the ratchet-wheel, and a crank 48 upon the latter projects through a hole 49 in the mask. The ratchetwheel is in the form of a disk, in which are punched openings 50 to form a series of spokes 51, the mask being formed into if corresponding spokes 52, which are flanged at 53, so that the ratchet-wheel is given a generally finished appearance. These parts, together with a ribbon-reversing wheel 54,

are held upon the left-hand end of shaft 34 by means of a nut 55, which screws upon a threaded nipple 56 formed by reducing the end of the shaft. Between the nipple and the shaft is also formed a squared shoulder 57, upon which fits squared central peri forations 58, 59 in wheel 54 and ratchetwheel 33. The mask has a small round central perforation which fits upon the nipple 56.

When the ribbon is nearly all reeled off is therefore enabled to swing the latter as 1:

the ribbon continues to pay off from the spool. This arm is mounted upon the top end of a vertical rock-shaft 63. The latter at its lower end is bent to form an arm 64 having a reduced end, from which is bent down a finger 65 to swing against a cam 66 that is formed upon an interponent 67. The interponent has a tooth 68 which swings into one of a series of notches 69 that are formed in ribbon-reversing wheel 54, fast to the winding shaft 34. When the interponent-tooth 68 is thus caught in a notch, the revolving wheel 54 effects a prolongation of the swing ing movement of the interponent 67, about its pivot 70, which may be concentric with the spool-shaft 44. The wheel 54 has a crowd ing or toggle action upon the swinging interponent 67 which reacts upon the wheel so that the latter is forced in a direction longitudinal of shaft 34, and drags the shaft along, thus disconnecting one of the shaftpinions 40, 41, and connecting the other, so that the ribbon may begin to wind upon the empty spool.

It is noted that in repositioning each ribbon-spool and shaft-assemblage at the extreme side of the machine, in order to enable the ends of the carriage to clear the ribbonspools, the reversing wheel 54 has been brought very close to the winding ratchet 33. It is given a japanned outer surface, or one of the same color as the mask 46, and cooperates therewith to lend attractiveness to the ratchet-wheel structure, and has the neat appearance of forming a part of the ratchetwheel.

In place of the usual practice of forming a cam-arm separately and attaching it to the shaft 63, the lower end of said shaft is bent to form said arm 64, and the latter is reduced at its free end, and the reduced portion is bent down to form finger 65 which engages said cam 66. It is evident that none of these parts can become loose or drop off.

The shaft 63 is supported by means of a collar 73 on a lug 74 cast upon the ribbonbracket 75; and the shaft is prevented from riding upwardly by means of an attached collar 76 placed below a lug 77. To form an improved connection between the collar 73 and the ribbon-operated arm 62, for which said collar serves as a hub, the hub is riveted at 78 to the arm 62; and relative looseness is prevented by means of a key which is in the form of a pin 79 that is driven partly into the reduced and riveted end of the hub 78 and partly into the material of the arm 62.

Said pin 79 serves also as an anchorage or connection for a tension-spring 80, which returns the arm 62 to normal position when the direction of winding of the ribbon has been reversed. This spring 80 is attached at its other end to a pin 81, on a spool-housing 82. This housing may be swung by a handle 83 around shaft 44 which it loosely engages, thereby positioning the housing to afford access to the spool and ribbon for threading the latter in the customary manner. The spring 80 serves for returning both the arm 62 and the housing-member 82.

The hub 73 is fastened upon the top of the shaft 63 by means of a set-screw 84, which bears upon a flattened portion 85 on the tip of the shaft. The finger 65 usually enters a notch 86 in the interponent 67, to lock the same against accidental movement.

The universal bar is not operated by the type-bars until they approach the platen, so that a gain is effected by operating the ribbon-winder positively at the printing strokes of the type-bars. The difiiculty is avoided of forcing a type-bar, as it approaches the platen, to tension a returning spring sufii ciently to operate the ribbon-winder on the return-stroke of the type-bar. The spring can be made weak, as it has only to return the ribbonqvinding pawl, and this diminution of resistance to the type-bar at this time is important.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine having ribbon-spools, a horizontal winding shaft for the spools, said shaft carrying wheels to shift the same endwise, and normally idle ribbonreversing interponents co-operatively asso ciated with said wheels, to shift the shaft to and fro endwise; a vertical shaft at each side of the machine and detachably mounted and having an arm operable by an obstruction on the ribbon, and a spring for returning said arm, said vertical shaft at its lower end formed into a crank-arm, said crank-arm formed with a finger to engage the interponent to operate the same, said ribbon-operated arm having a hub, said arm being keyed to said hub by means of a pin which forms an anchorage for said arm-returning spring.

2. In a typewriting machine having ribbonspools, a horizontal winding shaft for the spools, said shaft carrying wheels to shift the same endwise, and normally idle ribbonreversing interponents co-operatively associated with said wheels, to shift the shaft to and fro endwise; a vertical shaft at each side of the machine and having an arm operable by an obstruction on the ribbon, each vertical shaft at its lower end bent to form a crankarm, said crank-arm having a finger bent to engage the interponent to operate the same, said ribbon-operated arm having a hub, means detachably securing said hub upon the tip of said shaft, said arm being keyed to said hub, and an arm-returning spring, the ribbon enclosed in a housing which is movable to afford access to the ribbon and spool, and said spring being also connected to said movable housing to return the same.

WILLIAM F. HELMOND. 

